• 한국발생생물학회지:발생과생식
• /
• 제5권2호
• /
• pp.101-106
• /
• 2001

Insulin과 tumor necrosis factor alpha(TNF-$\alpha$)에 의한 초기 배아 발생의 조절기작을 알아보고자 생쥐의 상실배를 대상으로 이들이 첨가된 배양액에서 형태발생, 세포증식을 조사하고, 포배에서 mitogen activated protein kinase(MAPK, ERK1/2)의 활성 변화에 미치는 영향을 조사하였다. Insulin은 상실배의 체외발생 및 포배내 할구 수를 대조군에 비해 유의하게 증가시켰으며, TNF-$\alpha$는 발생율을 유의하게 감소시켰다. Insulin은 TNF- $\alpha$에 의한 배아 발생율 감소를 완화하였다. TNF-$\alpha$는 농도에 의존적으로 MAPK 활성을 감소시켰으며, insulin은 포배에서 MAPK의 활성을 유의하게 증가시킨 반면 TNF-$\alpha$는 처리농도에 의존적으로 MAPK 활성을 감소시켰다. 50 ng/ml 농도의 TNF-$\alpha$를 전처리한 포배에서는 insulin에 의한 MAPK 활성의 증가가 저해되었다. 이러한 결과로부터 생쥐의 착상전 초기 배아 발생조절에 insulin과 TNF-$\alpha$ 사이에 MAPK를 경유하는 cross talk이 존재함을 확인하였고 insulin은 TNF-$\alpha$ 에 의한 배아의 손상을 억제하는 것으로 사료된다.

• Biomolecules & Therapeutics
• /
• 제21권4호
• /
• pp.258-263
• /
• 2013

We demonstrate herein that silibinin, a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), inhibits LPS-induced activation of macrophages and production of nitric oxide (NO) in RAW 264.7 cells. Western blot analysis showed silibinin inhibits iNOS gene expression. RT-PCR showed that silibinin inhibits iNOS, TNF-${\alpha}$, and $IL1{\beta}$. We also showed that silibinin strongly inhibits p38 MAPK phosphorylation, whereas the ERK1/2 and JNK pathways are not inhibited. The p38 MAPK inhibitor abrogated the LPS-induced nitrite production, whereas the MEK-1 inhibitor did not affect the nitrite production. A molecular modeling study proposed a binding pose for silibinin targeting the ATP binding site of p38 MAPK (1OUK). Collectively, this series of experiments indicates that silibinin inhibits macrophage activation by blocking p38 MAPK signaling.

• IMMUNE NETWORK
• /
• 제5권4호
• /
• pp.237-246
• /
• 2005

Background: Little information is available on the identification and characterization of the upstream regulators of the signal transduction cascades for Mycobacterium tuberculosis (M. tbc)-induced ERK 1/2 activation and chemokine expression. We investigated the signaling mechanisms involved in expression of CCL3 /MIP-1 and CCL4/MIP-1 in human primary monocytes infected with M. tbc. Methods: MAP kinase phosphorylation was determined using western blot analysis with specific primary antibodies (ERK 1/2, and phospho-ERK1/2), and the upstream signaling pathways were further investigated using specific inhibitors. Results: An avirulent strain, M. tbc H37Ra, induced greater and more sustained ERK 1/2 phosphorylation, and higher CCL3 and CCL4 production, than did M. tbc H37Rv. Specific inhibitors for mitogen-activated protein kinase (MAPK) kinase (MEK; U0126 and PD98059) significantly inhibited the expression of CCL3 and CCL4 in human monocytes. Mycobactetia-mediated expression of CCL3 and CCL4 was not inhibited by the Ras inhibitor manumycin A or the Raf-1 inhibitor GW 5074. On the other hand, phospholipase C (PLC) inhibitor (U73122) and protein kinase C (PKC)specific inhibitors ($G\ddot{o}6976$ and Ro31-8220) significantly reduced M. tbc-induced activation of ERK 1/2 and chemokine synthesis. Conclusion: These results are the first to demonstrate that the PLC-PKC-MEK-ERK, not the Ras-Raf-MEK-ERK, pathway is the major signaling pathway inducing M. tbc-mediated CCL3 and CCL4 expression in human primary monocytes.

• 대한통합의학회지
• /
• 제12권1호
• /
• pp.1-10
• /
• 2024

Purpose: Lycopene is abundantly contained in Tomatoes and is known for diverse biological activities such as antioxidant, anti-inflammatory, and anticancer effects. In this study, the antioxidative potential of lycopene was investigated through the induction of hemeoxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor2 (Nrf2) and upstream signaling molecules, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Aktin RAW 264.7 cells. Methods: The antioxidative potential of lycopene against oxidative stress and its molecular mechanisms were determined by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results: Lycopene treatment significantly attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS formation in a dose-dependent manner without any cytotoxicity. In addition, 50 µM of lycopene for 6 h treatment induced potent HO-1 expression and its transcription factor, Nrf2. MAPK and PI3K/Aktwere also analyzed due to their critical roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, phosphorylation of extracellular regulated kinase (ERK) was significantly induced by lycopene treatment while the activated status of c-Jun NH2-terminal kinase (JNK), p38, and Akt, were not given any effect. To confirm the antioxidative mechanism of HO-1 mediated by ERK activation, each selective inhibitor was employed in a protection assay, in which oxidative damage occurred by t-BHP. Lycopene, SnPP, and CoPP treatments reflected accelerated HO-1 expression could be a protective role against oxidative damage-initiated cell death. A selective inhibitor for ERK significantly inhibited the lycopene-induced cytoprotective effect but selective inhibitors for other signaling molecules did not attenuate the rate of t-BHP-induced cell death. Conclusion: In conclusion, lycopene potently scavenged intracellular ROS formation and enhanced the HO-1 mediated antioxidative potential through the modulation of Nrf2, MAPK signaling pathway in RAW 264.7 cells.

• 동의생리병리학회지
• /
• 제22권4호
• /
• pp.841-848
• /
• 2008

Archyranthes radix has had extensive therapeutic application, and there has been increasing interest in its biological effects. However, the biochemical effects of Archyranthes radix on chondrocyte oxidative stress have never been systematically investigated. Therefore, we investigated the effects of Acyranthes radix on role of MAPK signal transduction pathway on oxidative stress induced by hydrogen peroxide in rat articular chondrocytes. The statistically significant inhibitory action of Archyranthes radix on cell proliferation was observed at above $5{\mu}g/m{\ell}$. Next, we examined the time-dependent effect of $5{\mu}g/m{\ell}$ Archyranthes radix on cell proliferaion. Archyranthes radix significantly inhibited cell proliferation from 12 hr after treatment (P<0.05). $H_2O_2$, resulted in a time- and dose-dependent cell proliferation, which was largely attributed to oxidative damage. Acyranthes radix and $H_2O_2$ treatment caused marked sustained activation of phosphorylation of ERK1/2. Moreover, the synergistic phosphorylation of p44/42 MAPK by $H_2O_2$ and Archyranthes radix was selectively inhibited by PD 98059, a p44/42 MAPK inhibitor. In conclusion, these results are consistent with the hypothesis that under conditions of oxidative stress, the $H_2O_2$-induced inhibition of cell proliferation in the rat chondrocyte is mediated through a modulation of the Archyranthes radix signaling pathway, promoting further phosphorylation of p44/42 MAPK, indicating a potentially important role in cartilage repair and in the treatment of osteoarthritic cartilage.

• BMB Reports
• /
• 제49권8호
• /
• pp.437-442
• /
• 2016

We aimed to study the role of protein L-isoaspartyl methyltransferase (PIMT) in neuronal differentiation using basic fibroblast growth factor (bFGF)-induced neuronal differentiation, characterized by cell-body shrinkage, long neurite outgrowth, and expression of neuronal differentiation markers light and medium neurofilaments (NF). The bFGF-mediated neuronal differentiation of PC12 cells was induced through activation of mitogen-activated protein kinase (MAPK) signaling molecules [MAPK kinase 1/2 (MEK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), and p90RSK], and phosphatidylinositide 3-kinase (PI3K)/Akt signaling molecules PI3Kp110β, PI3Kp110γ, Akt, and mTOR. Inhibitors (adenosine dialdehyde and S-adenosylhomocysteine) of protein methylation suppressed bFGF-mediated neuronal differentiation of PC12 cells. PIMT-eficiency caused by PIMT-specific siRNA inhibited neuronal differentiation of PC12 cells by suppressing phosphorylation of MEK1/2 and ERK1/2 in the MAPK signaling pathway and Akt and mTOR in the PI3K/Akt signaling pathway. Therefore, these results suggested that PIMT was critical for bFGF-mediated neuronal differentiation of PC12 cells and regulated the MAPK and Akt signaling pathways.

• Journal of Nutrition and Health
• /
• 제49권4호
• /
• pp.241-246
• /
• 2016

Purpose: Aloe-emodin (AE), an ingredient of aloe, is known to exhibit anti-inflammatory activities. However, little is known about the underlying molecular mechanisms of its inflammatory modulatory activity in vitro. In the present study, we investigated the anti-inflammatory potential of AE using $Pam_3CSK_4$-stimulated macrophages. Methods: RAW 264.7 macrophages were treated with AE (0~20 mM) for 1 h, followed by treatment with $Pam_3CSK_4$ for 1 h. After incubation, mRNA expression levels of cytokines were measured. The effect of AE on TLR2-related molecules was also investigated in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Results: AE attenuated $Pam_3CSK_4$-stimulated expression of proinflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and interleukin-$1{\beta}$ ($IL-1{\beta}$) in RAW 264.7 macrophages. Two concentrations of AE ($10{\mu}M$ and $20{\mu}M$) effectively reduced mRNA expression of TLR2 by 41.18% and 54.43%, respectively, compared to that in control cells (p < 0.05). AE also decreased nuclear factor-kappa B ($NF-{\kappa}B$) activation and mitogen-activated protein kinase (MAPK) phosphorylation. Phosphorylation levels of ERK1/2, p38, and JNK were markedly reduced by $20{\mu}M$ AE. In particular, AE decreased phosphorylation of ERK in a dose-dependent manner in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Conclusion: Our data indicate that AE exerts its anti-inflammatory effect by suppressing TLR2-mediated activation of $NF-{\kappa}B$ and MAPK signaling pathways in macrophages.

• Childhood Kidney Diseases
• /
• 제21권1호
• /
• pp.1-7
• /
• 2017

Mitogen-activated protein kinases (MAPKs) play important roles in various cellular functions including proliferation, differentiation, and apoptosis. We showed that MAPKs are developmentally regulated in the rat kidney. p38 MAPK (p38) and extracellular signal-regulated kinase (ERK) were strongly expressed in the fetal kidney, whereas c-Jun N-terminal kinase (JNK) was detected predominantly in the adult kidney. The inhibition of p38 or ERK in organ culture resulted in reduced nephron formation with or without reduced kidney size. On the other hand, persistent fetal expression pattern of MAPKs, i.e., upregulation of p38 and ERK and downregulation of JNK, was observed in the cyst epithelium of human renal dysplasia, ovine fetal obstructive uropathy, and pcy mice, a model of polycystic kidney disease. Furthermore, activated p38 and ERK induced by cyclic stretch mediated proliferation and $TGF-{\beta}1$ expression in ureteric bud cells, probably leading to cyst formation and dysplastic changes. Inhibition of ERK slowed the disease progression in pcy mice. Finally, ERK and p38 were inactivated in the early embryonic kidney subjected to maternal nutrient restriction, characterized by reduced ureteric branching and nephron number. Thus, MAPKs mediate the development of normal and diseased kidney. Their modulation may result in novel therapeutic strategies against developmental abnormalities of the kidney.

• 한국가금학회지
• /
• 제44권3호
• /
• pp.199-209
• /
• 2017

Mitogen-activated protein kinase (MAPK) signaling pathways play a key role in innate immunity, inflammation, cell proliferation, cell differentiation, and cell death. The main objective of this study was to investigate the expression level of candidate MAPK pathway genes in the intestinal mucosal layer of two genetically disparate chicken lines (Marek's disease-resistant line 6.3 and Marek's disease-susceptible line 7.2) induced with necrotic enteritis (NE). Using high-throughput RNA sequencing, we investigated 178 MAPK signaling pathway related genes that were significantly and differentially expressed between the intestinal mucosal layers of the NE-afflicted and control chickens. In total, 15 MAPK pathway genes were further measured by quantitative real-time PCR(qRT-PCR) and the results were consistent with the RNA-sequencing data. All 178 identified genes were annotated through Gene Ontology and mapped onto the KEGG chicken MAPK signaling pathway. Several key genes of the MAPK pathway, ERK1/2, JNK1-3, p38 MAPK, MAP2K1-4, $NF-{\kappa}B1/2$, c-Fos, AP-1, Jun-D, and Jun, were differentially expressed in the two chicken lines. Therefore, we believe that RNA sequencing and qRT-PCR analysis provide resourceful information for future studies on MAPK signaling of genetically disparate chicken lines in response to pathogens.

• 동의생리병리학회지
• /
• 제24권1호
• /
• pp.80-84
• /
• 2010

Codonopsis Lanceolata (CL) has been widely used in Oriental medicine for treatment of chronic inflammatory diseases, such as bronchitis, cough, and spasm; however, the mechanism of its anti-inflammatory activity has not been clarified. In this study, therefore, we investigated the inhibitory effect of CL on LPS-induced inflammation. The effect of CL was analyzed by ELISA, RT-PCR and Western blotting in LPS-stimulated RAW264.7 cells. We found that CL suppressed not only the mRNA expression of pre-inflammatory cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2, but also the phosphorylation of ERK1/2, JNK1/2 and p38 MAPK. These results suggest that CL exerts an anti-inflammatory effect through the regulation of the mitogen-activated protein kinases (MAPK) pathway, thereby decreasing production of pre-inflammatory cytokines, NO, and PGE2.